Every year, millions of people in the U.S. suffer head and brain injuries. Some are minor because the skull is quite good at protecting the brain. More than half are bad enough that people must go to the hospital. Serious head injuries can lead to permanent brain damage or death.

Minor head injuries usually heal without treatment. Serious head injuries need emergency treatment. Indications that a head injury may be serious include
o    A headache that gets worse or does not go away
o    Repeated vomiting or nausea
o    Convulsions or seizures
o    An inability to awaken from sleep
o    Dilation of one or both pupils of the eyes
o    Slurred speech
o    Weakness or numbness in the arms or legs
o    Loss of coordination
o    Increased confusion, restlessness or agitation

A traumatic brain injury occurs when an outside force impacts the head hard enough to cause the brain to move within the skull; or, if the force causes the skull to break and directly hurts the brain. A direct force to the head can be great enough to injure the brain inside the skull. It can also break the skull and directly hurt the brain. This type of injury can occur from motor vehicle crashes, guns, falls, sports, and physical violence.

A rapid acceleration and deceleration of the head can force the brain to move back and forth across the inside of the skull. The stress from the rapid movements pulls apart nerve fibers and causes damage to brain tissue. This type of injury often occurs as a result of motor vehicle crashes and physical violence, such as Shaken Baby Syndrome.

Diffuse Nerve Injury can be caused by shaking or strong rotation of the head, as with Shaken Baby Syndrome, or by rotational forces, such as with a car accident.  Injury occurs because the unmoving brain lags behind the movement of the skull, causing brain structures to tear.  There is extensive tearing of nerve tissue throughout the brain. This can cause brain chemicals to be released, causing additional injury.  The tearing of the nerve tissue disrupts the brain’s regular communication and chemical processes.  This disturbance in the brain can produce temporary or permanent widespread brain damage, coma, or death.

Concussion is the most common type of traumatic brain injury.  Concussion can be caused by direct blows to the head, gunshot wounds, violent shaking of the head, or force from a whiplash type injury. Skull fracture, brain bleeding, or swelling may or may not be present. The blood vessels in the brain may stretch and cranial nerves may be damaged.  A person may or may not experience a brief loss of consciousness.  A person may remain conscious, but feel “dazed” or “punch drunk”.   A concussion may or may not show up on a test such as a CAT Scan. Shaken Baby Syndrome can cause seizures, lifelong disability, coma, and death.  Irritability, changes in eating patterns, tiredness, difficulty breathing, dilated pupils, seizures, and vomiting are signs of Shaken Baby Syndrome. A baby experiencing such symptoms needs immediate emergency medical attention.

Contusion is a bruise on the brain and can be the result of a direct impact to the head. 
 
Penetrating injury to the brain occurs from the impact of a bullet, knife or other sharp object that forces hair, skin, bone and fragments from the object into the brain.  Firearms are the single largest cause of death from traumatic brain injury.

Cells in the brain need oxygen to survive and function.  Anoxic Brain Injury occurs when the brain does not receive any oxygen.  Hypoxic Brain Injury results when the brain receives some, but not enough oxygen.  Causes of anoxic/hypoxic brain injury can include, but are not limited to:
o    Airway obstruction
o    Near-drowning,
o    Throat swelling,
o    Choking,
o    Strangulation,
o    Crush injuries to the chest
o    Electrical shock or lightening strike
o    Trauma to the head and/or neck
o    Traumatic brain injury
o    Vascular disruption
o    Heart attack, stroke
o    Infectious disease
o    Intracranial tumors
o    Illegal drug use, alcohol abuse,
o    Lead, carbon monoxide poisoning,
o    Toxic chemicals, chemotherapy Severe brain injury occurs when a prolonged unconscious state or coma lasts days, weeks, or months. Severe brain injury is further categorized into subgroups with separate features:
·    Coma
o    Coma is defined as a state of unconsciousness from which the individual cannot be awakened, in which the individual responds minimally or not at all to stimuli, and initiates no voluntary activities.
o    Persons in a coma appear to be asleep, but cannot be awakened
o    There is no meaningful response to stimulation.
·    Vegetative State
o    Arousal is present, but the ability to interact with the environment is not.
o    Eye opening can be spontaneous or in response to stimulation
o    General responses to pain exist, such as increased heart rate, increased respiration, posturing, or sweating
o    Sleep-wakes cycles, respiratory functions, and digestive functions return
·    Persistent Vegetative State
o    Persistent Vegetative State (PVS) is used for a Vegetative State that has lasted for more than a month. 
o    The use of this term is considered controversial because it implies a prognosis.
·    Minimally Responsive State
o    a person is no longer in a coma or a Vegetative State
o    Persons in a Minimally Responsive State demonstrate:
§    Primitive reflexes
§    Inconsistent ability to follow simple commands
§    An awareness of environmental stimulation

When a person receives an impact to the head from an outside force, it can injure the skin, skull, and the brain.
Persons with a traumatic brain injury may or may not have visible skin injuries on their head.  When the head receives an impact from an outside source, if the brain is injured the brain may swell.  If the skull is fractured or displaced, bone fragments from the skull can enter the brain and cause further injury.   The brain is now exposed, which leaves it vulnerable to infections and further injury.

When a person receives an impact to the head from an outside force, but the skull does not fracture or displace it is a "closed head injury".  With a closed head injury, when the brain swells, the brain has no place to expand. This can cause an increase in pressure within the skull.  Brain tissues compress, causing further injury.  It can compress and impair the functions of the eye nerves.

All traumatic head injuries need to be evaluated by a physician.  In many cases, prompt/emergency treatment can prevent long term or permanent loss of brain function.  Remember, our brains control not only thinking, feeling and judging, but also the integrity of our 5 senses and our ability to move in a purposeful and coordinated way.  Prompt attention to injury to the head is essential in promoting brain health, and, of course, care and safety in preventing or reducing risk of head injury is even more critical.  So break out those bike helmets, wear your seatbelt and stop smacking yourself in the head every time you could have had a V-8!